Chapter 15, Problem 58QP

Interpretation Introduction

Interpretation:

The position of equilibrium according to the given conditions for the given reaction is to be determined.

Concept introduction:

The equilibrium constant is defined as the ratio of concentration of products to that of reactants. It depends on the temperature of the reaction and independent of the initial concentrations of the reactants.

Le Chatelier’s principle is used to explain the change in pressure, temperature or concentration of the equilibrium shifts into the direction in which effect change from the system.

For a general reaction: $a\text{A}\text{+}b\text{B}\rightleftarrows c\text{C}\text{+}d\text{D}$

Reaction quotient is defined as the ratio of concentration of products and reactants of chemical species present in the reaction mixture at a given point of time. It is denoted with $\text{Q}$.

$\text{Reaction quotient, }{Q}_c=\frac{{\left[\text{C}\right]}^{\text{c}}{\left[\text{D}\right]}^{\text{d}}}{{\left[\text{A}\right]}^{\text{a}}{\left[\text{B}\right]}^{\text{b}}}$

Equilibrium constant is defined as the ratio of concentration of products and the concentration of reactants, which are in equilibrium, and its value is constant at a particular temperature. It denoted by K.

$\text{Equilibrium constant, }{K}_c=\frac{{\left[\text{C}\right]}^{\text{c}}{}_{\text{eqm}}{\left[\text{D}\right]}^{\text{d}}{}_{\text{eqm}}}{{\left[\text{A}\right]}^{\text{a}}{}_{\text{eqm}}{\left[\text{B}\right]}^{\text{b}}{}_{\text{eqm}}}$

Here, $K_C$ is the equilibrium constant and $C$ in $K_C$ stands for the concentration. $\left[\text{A}\right]$, $\left[\text{B}\right]$, $\left[\text{C}\right]$, and $\left[\text{D}\right]$ are the equilibrium concentration of reactants A and B and product C and D, respectively.

A and B are reactants, C and D are products, and $a,b,c$, and $d$ are their respective stoichiometric coefficients.

At equilibrium, $Q_c=K_c$

The equilibrium concentration of reactants and products, present in liquid or solid phase, in the reaction is considered to be $1$ in the expression of equilibrium constant.